PP1506 - Sensitivity of Path Length as a Measure in Assessing Post-Concussion Imbalance Utilizing the Modified Clinical Test of Sensory Integration

Objective: The main objective of this study is to assess if path length provides improved identification of post-concussion imbalance using the modified Clinical Test of Sensory Integration of Balance (mCTSIB).  

Rationale: Mild traumatic brain injury (mTBI), also referred to as a concussion, can occur when trauma to the head or to the body causes the brain to move quickly back and forth. It can affect sensory, cognitive, and motor function. According to data reported by the Centers for Disease Control, dizziness and imbalance following concussion are among the most common symptoms, estimated to occur in 23%-81% of cases in the first days following injury. Measuring the motor domain of neurologic function is valuable to assess concussion patients. The modified Clinical Test of Sensory Integration of Balance (mCTSIB) is a test evaluating sensory integration. Currently, mCTSIB uses center of gravity (COG) as the measure of postural stability. COG is the net location of the center of mass in the vertical direction. We have found that when using COG as a measure of sensory integration, a subset of patients demonstrate balance patterns historically identified as physiologically inconsistent. We propose that using additional metrics, such as path length, may provide improved identification of post-concussion imbalance.  

Design: Retrospective study of balance performance of 76 patients with post-concussion symptoms compared with typical control subjects (n=25). Total Distance for each condition were compared between groups. 

Results:  Preliminary data include 76 patients at initial presentation for post-concussion symptoms.  The majority (84%, n=64) presented within 3 months of injury and described symptoms of vertigo (32%, n=24), lightheadedness (36%, n=27), and imbalance (54%, n=41).  Mean Post Concussion Symptom Score (PCSS) severity was 54 (SD: 27, range: 2-90).  Regarding Total Distance, there was a significant difference between post-concussion patients and control data for condition 1 (M=5.48, SD=4.13; t(92)=-3.16, p=0.0022), condition 2 (M=7.99, SD=5.27; t(92)=-4.20, p<0.001), condition 3 (M=8.02, SD=3.86; t(79)=-2.95, p<0.001), and condition 4 (M=18.11, SD=6.23; t(79)=-4.07, p<0.001).  These findings remained significant after Bonferroni correction for multiple comparisons.  When considering the ability to identify abnormal performance between groups, the 95th percentile was calculated for each condition from the control group data (condition 1: 4.0977; condition 2: 5.0037; condition 3: 7.4086; condition 4: 17.7756).  Those who exceeded the 95th percentile were identified: condition 1: 52% (n=36); condition 2: 70% (n=48); condition 3: 45% (n=25); condition 4: 41% (n=23).  When compared to traditional COG measures, 11 more patients were identified with poorer balance performance than expected, with 5 and 6 additional patients noted in conditions 3 and 4, respectively. 

Conclusions: Identifying patients with significant imbalance is an important component of appropriate patient management post-concussion.  Traditional metrics, such as COG, may not be sufficient to identify subtle changes in balance performance, especially in conditions with large expected variability.  Use of additional metrics, such as Total Distance, may provide additional insight into the often subtle imbalance present in patients post-concussion.